fix browser build

Co-authored-by: Copilot <copilot@github.com>

Author: gingerbenw

packages/browser/package.json

@@ -2,9 +2,20 @@
   "name": "@bugsnag/browser",
   "version": "8.8.1",
   "main": "dist/index-cjs.js",
-  "types": "dist/types/index-es.d.ts",
+  "module": "dist/index-es.mjs",
+  "types": "dist/types/index-cjs.d.cts",
   "browser": "./dist/bugsnag.js",
   "sideEffects": false,
+  "exports": {
+    ".": {
+      "types": {
+        "import": "./dist/types/index-es.d.mts",
+        "require": "./dist/types/index-cjs.d.cts"
+      },
+      "import": "./dist/index-es.mjs",
+      "require": "./dist/index-cjs.js"
+    }
+  },
   "description": "Bugsnag error reporter for browser JavaScript",
   "homepage": "https://www.bugsnag.com/",
   "repository": {
@@ -22,6 +33,7 @@
     "clean": "rm -fr dist && mkdir dist",
     "prebuild": "npm run clean",
     "build": "rollup --config rollup.config.mjs",
+    "postbuild": "node scripts/fix-cjs-types.js",
     "cdn-upload": "../../bin/cdn-upload dist/*"
   },
   "author": "Bugsnag",

packages/browser/rollup.config.mjs

@@ -92,7 +92,7 @@ export default [
       {
         ...sharedOutput,
         preserveModules: false,
-        entryFileNames: '[name].js',
+        entryFileNames: '[name].mjs',
         format: 'esm'
       }
     ],
@@ -107,6 +107,8 @@ export default [
         ...sharedOutput,
         entryFileNames: '[name].js',
         format: 'cjs',
+        exports: 'default',
+        interop: 'compat'
       },
     ],
     plugins,

packages/browser/scripts/fix-cjs-types.js

@@ -0,0 +1,32 @@
+#!/usr/bin/env node
+
+/**
+ * Post-build script to create proper type declaration files
+ * - CJS types with 'export =' syntax
+ * - ESM types with .d.mts extension for proper module detection
+ */
+
+const fs = require('fs');
+const path = require('path');
+
+// Fix CommonJS types: change 'export default' to 'export ='
+const cjsSourceFile = path.join(__dirname, '../dist/types/index-cjs.d.ts');
+const cjsTargetFile = path.join(__dirname, '../dist/types/index-cjs.d.cts');
+
+let cjsContent = fs.readFileSync(cjsSourceFile, 'utf8');
+cjsContent = cjsContent.replace(
+  /export default (_default);/,
+  'export = $1;'
+);
+fs.writeFileSync(cjsTargetFile, cjsContent);
+console.log('Created CommonJS type declaration: dist/types/index-cjs.d.cts');
+
+// Fix ESM types: copy to .d.mts extension and add .js extensions to relative imports
+const esmSourceFile = path.join(__dirname, '../dist/types/index-es.d.ts');
+const esmTargetFile = path.join(__dirname, '../dist/types/index-es.d.mts');
+
+let esmContent = fs.readFileSync(esmSourceFile, 'utf8');
+// Add .js extensions to relative imports for Node16 ESM resolution
+esmContent = esmContent.replace(/from '(\.\/.+?)';/g, "from '$1.js';");
+fs.writeFileSync(esmTargetFile, esmContent);
+console.log('Created ESM type declaration: dist/types/index-es.d.mts');